Only shadow ARGB windows with a frame outside the frame

An ARGB window with a frame is likely something like a transparent
terminal. It looks awful (and breaks transparency) to draw a big
opaque black shadow under the window, so clip out the region under
the terminal from the shadow we draw.

Add meta_window_get_frame_bounds() to get a cairo region for the
outer bounds of the frame of a window, and modify the frame handling
code to notice changes to the frame shape and discard a cached
region. meta_frames_apply_shapes() is refactored so we can extract
meta_frames_get_frame_bounds() from it.

https://bugzilla.gnome.org/show_bug.cgi?id=635268

NOTE: Applied only partially, compositor part is still missing...

upstream commit:
https://gitlab.gnome.org/GNOME/metacity/commit/0f2e32d1

1 files changed, 4 insertions, 0 deletions

diff --git a/src/core/window-private.h b/src/core/window-private.h
index 38184231..50bc57be 100644
--- a/src/core/window-private.h
+++ b/src/core/window-private.h
@@ -41,6 +41,7 @@
 #include "stack.h"
 #include "iconcache.h"
 #include <X11/Xutil.h>
+#include <cairo.h>
 #include <gdk-pixbuf/gdk-pixbuf.h>
 #include <gtk/gtk.h>
 
@@ -324,6 +325,9 @@ struct _MetaWindow
   /* if TRUE, application is buggy and SYNC resizing is turned off */
   guint disable_sync : 1;
 
+  /* if non-NULL, the bounds of the window frame */
+  cairo_region_t *frame_bounds;
+
   /* Note: can be NULL */
   GSList *struts;